For protecting wood from destroying organisms, it is well known to impregnate wood with preservatives. Typical impregnating techniques used include pressure impregnation, dipping, surface treatment and the like.
In order that these protective treatments be effective, the following two requirements must be met independent of a particular impregnation technique. The first requirement is that impregnated wood is fully toxic to wood destroying organisms such as wood boring beetles, termites and decay fungi. It is also required that the preservative penetrate into the wood interior. Most wood preservatives satisfy the first requirement, but few satisfy the second requirement. There are frequent accidents that impregnated wood is degraded from the interior where little of the preservative reaches. An improvement in this regard is desired.
The penetration of preservatives may be improved by dissolving the preservatives in organic solvents or by adding small amounts of surfactants to aqueous preservatives. The dissolution in organic solvents is noticeably effective due to the low surface tension of organic solvents, but undesirable because of the problems of environmental pollution and volatile organic compounds (VOC). The addition effect of ordinary surfactants is limited, with few exerting satisfactory effects.
Prior Art 1: Yuji Imamura, the Japan Wood Society researcher meeting report entitled “Wood Chemistry and Utilization Technology II,” No. 2, the Japan Wood Society, pp. 21-38 (1991)
Prior Art 2: JP-A 08-197509
Prior Art 3: JP-A 08-198711
Prior Art 4: JP-A 10-007502